Indeed. I was rather shocked to hear a friend had be subpoenaed for a DNA swab based on phone tracking data, along with a handful of other men, in connection with a rape case that happened early in the morning (so few phones in the area). The idea was two-fold a) rule out suspects, and b) (presumably) get in touch with potential witnesses. While everyone wants the guilty party to get caught, I'm unsure what options one would have about refusing such a swab. In theory that swab wouldn't be held on file (but who can know if there is a secret backup of such data -- we don't have adequate oversight in Norway either).

They can already get your mobile records during a court ordered investigation. That information includes where you were and who you were with. Or rather where your phone was and who your phone was with.